"the system administrator will need to install and configure
sssd to replace it after the update. Even when this is not done, the
only visible affect will be slower resolution of named service queries
due to a missing cache."
I use nscd on a few application servers that point to unreliable DNS servers that we have no control over (thanks to our Microsofties) and find caching only the positive responses smooths things out very well.
From the day ncsd was created it has always been easy to set up and always had funny execution quirks. My nscd implementation occasionally bloats to 600Mb of memory usage just on host caching but fortunately nscd has an auto restart feature which I've set to run daily to cure this.
Definitely happy to throw nscd out for something better that was just as simple and easy to set up. Unfortunately sssd is quite sophisticated and therefore complex, and does caching secondary from its main purpose which seems overkill if that was the only reason for running it. I'll leave systemd-resolved for the trail blazers.
I'd still like to see nscd continue to be available but wholeheartedly agree it's showing its age.